Data type: numb
May appear in a looped list containing '_space_group_id'
Enumeration range: 1 -> 230
The number as assigned in International Tables for Crystallography Vol A, specifying the proper affine class (i.e. the orientation preserving affine class) of space groups (crystallographic space group type) to which the space group belongs. This number defines the space group type but not the coordinate system in which it is expressed.